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List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-orgmode-bounces+larch=yhetil.org@gnu.org Sender: emacs-orgmode-bounces+larch=yhetil.org@gnu.org X-Migadu-Flow: FLOW_IN X-Migadu-Country: US ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=yhetil.org; s=key1; t=1675243307; h=from:from:sender:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:mime-version:mime-version: content-type:content-type:in-reply-to:in-reply-to: references:references:list-id:list-help:list-unsubscribe: list-subscribe:list-post:dkim-signature; bh=Q+fCn7CMtyL3Hr22tX18Eop3Buxs4yf0Lh6GGTNvAes=; b=VH3UuESct2un+6/SI+BU61w8P7ViyngqKRAV6IMIFf7rnGjrou2cWmlgYMX/N1QSzItg8b of79qxbc3p2na51G0Wxf9aqo4FZhpQE0aVfC1/76Iuyw/Hc3Z2w+wgj/7q0MFfwZm562ck CGMS1XuZzMLgZOGwWqlSPjkk9JOJXtvAd1o9RUNzExSoKV9vIqeZumqy64dpLG+s9qSTDH vCoXlPi8v5GWImn9Gcxp1Wsk2A7BBL8V4vbHfKV/rcB/alWcVMZcSiA1EkG/SzWAiq6zLl Wo7XV8vFwSfNzHyjt2ckuNkZheUCAy1QeDxVfHTaU69aJmbUwH190DSJvYXSNA== ARC-Authentication-Results: i=1; aspmx1.migadu.com; dkim=fail ("headers rsa verify failed") header.d=tuxteam.de header.s=mail header.b=UKSZNSdt; spf=pass (aspmx1.migadu.com: domain of "emacs-orgmode-bounces+larch=yhetil.org@gnu.org" designates 209.51.188.17 as permitted sender) smtp.mailfrom="emacs-orgmode-bounces+larch=yhetil.org@gnu.org"; dmarc=none ARC-Seal: i=1; s=key1; d=yhetil.org; t=1675243307; a=rsa-sha256; cv=none; b=PFDHyNsCGSfvMS3Z9AVWVgbjiraGe3e+YIgVqSzCzE2ckW0WXnCHSNigq908TIQe9MYgpJ EPKi7tSuQKY0IT4u9+wMVB2gEsoHEsdq0RnQAMkbzz7iWz3APK1hOWKI8+6aYLydhEG5Hq PRSSv/2syXM31L6Sx6kR9ZdlFYLcGI8nc1cfTBLi9Rjnj7mNKbuk7z9sKY58svVEf7Jq5H C4mRJ35d93vwOO4qlOwjbDFt3JTKoh4/m1jsGI9dIJgmMzR9A4ScuJpaTcR5bUi37lYdKi ZWcU5+QfbXQWr7JUq29P1LgBHTaaLEH05iLfgHSX76Ond2A5GXvAYL9Yf6ZWeg== Authentication-Results: aspmx1.migadu.com; dkim=fail ("headers rsa verify failed") header.d=tuxteam.de header.s=mail header.b=UKSZNSdt; spf=pass (aspmx1.migadu.com: domain of "emacs-orgmode-bounces+larch=yhetil.org@gnu.org" designates 209.51.188.17 as permitted sender) smtp.mailfrom="emacs-orgmode-bounces+larch=yhetil.org@gnu.org"; dmarc=none X-Migadu-Scanner: scn0.migadu.com X-Spam-Score: -3.28 X-Migadu-Queue-Id: CD82737BD1 X-Migadu-Spam-Score: -3.28 X-TUID: 8VrRCIgGyAGF --QhGHFpBKMGctxyHn Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Feb 01, 2023 at 10:06:15AM +0100, Stefan Nobis wrote: > writes: >=20 > > 2023-03-23 02:30 @Europe/Berlin refers to /two/ points in time, thus > > it /is/ ambiguous. >=20 > As far as I understand the definitions, the point in time "2023-03-23 > 02:30 @Europe/Berlin" is clearly defined as 2023-03-23 02:30 UTC+0100. >=20 > A bit more problematic would be "2023-03-26 02:30 @Europe/Berlin". [...] This has already been cleared in the thread: I got the year the wrong way around. > The real problem would be e.g. "2023-10-29 02:30 @Europe/Berlin". This > point in time really exist twice, there is 02A:30 (02:30 UTC+0200) and > 02B:30 (02:30 UTC+0100) in this night of switching back from DST to > normal time! >=20 > So, in general, only using the time zone name may indeed lead to > ambiguous interpretations of timestamps. =2E..which stems from the fact that the very concept of "time zone" is somewhat ambiguous, too. Some time zone designations carry the fact of whether they are supposed to be summer times or not with them (as with CET/CEST), some not (as above). The time zone database is only known for a limited time into future and may change with political vagaries. Yadda, yadda. If you really want to have fun with this (and this thread hasn't satisfied your thirst ;-) see [1]. Cheers [1] https://en.wikipedia.org/wiki/British_Summer_Time#Early_history --=20 t --QhGHFpBKMGctxyHn Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iF0EABECAB0WIQRp53liolZD6iXhAoIFyCz1etHaRgUCY9ou3gAKCRAFyCz1etHa RrHtAJ9zXQnu7UEt0oqWJ8NuGwaLiTcmfwCeIhIZ2Sslf9gkZcDAj/AkhmpHQdY= =00LS -----END PGP SIGNATURE----- --QhGHFpBKMGctxyHn--